class Animal {
    constructor(name) {
        this.name = name;
    }
    sayHi() {
        console.log(`${this.name} 打招呼`)
    }
}

class Dog extends Animal{
    constructor(name, type) {
        super(name);
        this.type = type
    } 
    sayHi() {
        console.log(`${this.name} 汪汪汪`);
    }
}
// js class extends super 只是语法糖, 原型式的面向对象
const dog = new Dog('大毛', '拉布拉多');
// console.log(dog);
console.log(dog.__proto__.__proto__.__proto__)

